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-rw-r--r--mesalib/src/glsl/ast_array_index.cpp190
1 files changed, 190 insertions, 0 deletions
diff --git a/mesalib/src/glsl/ast_array_index.cpp b/mesalib/src/glsl/ast_array_index.cpp
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+/*
+ * Copyright © 2010 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include "ast.h"
+#include "glsl_types.h"
+#include "ir.h"
+
+ir_rvalue *
+_mesa_ast_array_index_to_hir(void *mem_ctx,
+ struct _mesa_glsl_parse_state *state,
+ ir_rvalue *array, ir_rvalue *idx,
+ YYLTYPE &loc, YYLTYPE &idx_loc)
+{
+ if (!array->type->is_error()
+ && !array->type->is_array()
+ && !array->type->is_matrix()
+ && !array->type->is_vector()) {
+ _mesa_glsl_error(& idx_loc, state,
+ "cannot dereference non-array / non-matrix / "
+ "non-vector");
+ }
+
+ if (!idx->type->is_error()) {
+ if (!idx->type->is_integer()) {
+ _mesa_glsl_error(& idx_loc, state, "array index must be integer type");
+ } else if (!idx->type->is_scalar()) {
+ _mesa_glsl_error(& idx_loc, state, "array index must be scalar");
+ }
+ }
+
+ /* If the array index is a constant expression and the array has a
+ * declared size, ensure that the access is in-bounds. If the array
+ * index is not a constant expression, ensure that the array has a
+ * declared size.
+ */
+ ir_constant *const const_index = idx->constant_expression_value();
+ if (const_index != NULL && idx->type->is_integer()) {
+ const int idx = const_index->value.i[0];
+ const char *type_name = "error";
+ unsigned bound = 0;
+
+ /* From page 24 (page 30 of the PDF) of the GLSL 1.50 spec:
+ *
+ * "It is illegal to declare an array with a size, and then
+ * later (in the same shader) index the same array with an
+ * integral constant expression greater than or equal to the
+ * declared size. It is also illegal to index an array with a
+ * negative constant expression."
+ */
+ if (array->type->is_matrix()) {
+ if (array->type->row_type()->vector_elements <= idx) {
+ type_name = "matrix";
+ bound = array->type->row_type()->vector_elements;
+ }
+ } else if (array->type->is_vector()) {
+ if (array->type->vector_elements <= idx) {
+ type_name = "vector";
+ bound = array->type->vector_elements;
+ }
+ } else {
+ /* glsl_type::array_size() returns 0 for non-array types. This means
+ * that we don't need to verify that the type is an array before
+ * doing the bounds checking.
+ */
+ if ((array->type->array_size() > 0)
+ && (array->type->array_size() <= idx)) {
+ type_name = "array";
+ bound = array->type->array_size();
+ }
+ }
+
+ if (bound > 0) {
+ _mesa_glsl_error(& loc, state, "%s index must be < %u",
+ type_name, bound);
+ } else if (idx < 0) {
+ _mesa_glsl_error(& loc, state, "%s index must be >= 0",
+ type_name);
+ }
+
+ if (array->type->is_array()) {
+ /* If the array is a variable dereference, it dereferences the
+ * whole array, by definition. Use this to get the variable.
+ *
+ * FINISHME: Should some methods for getting / setting / testing
+ * FINISHME: array access limits be added to ir_dereference?
+ */
+ ir_variable *const v = array->whole_variable_referenced();
+ if ((v != NULL) && (unsigned(idx) > v->max_array_access)) {
+ v->max_array_access = idx;
+
+ /* Check whether this access will, as a side effect, implicitly
+ * cause the size of a built-in array to be too large.
+ */
+ check_builtin_array_max_size(v->name, idx+1, loc, state);
+ }
+ }
+ } else if (const_index == NULL && array->type->is_array()) {
+ if (array->type->array_size() == 0) {
+ _mesa_glsl_error(&loc, state, "unsized array index must be constant");
+ } else if (array->type->fields.array->is_interface()) {
+ /* Page 46 in section 4.3.7 of the OpenGL ES 3.00 spec says:
+ *
+ * "All indexes used to index a uniform block array must be
+ * constant integral expressions."
+ */
+ _mesa_glsl_error(&loc, state,
+ "uniform block array index must be constant");
+ } else {
+ /* whole_variable_referenced can return NULL if the array is a
+ * member of a structure. In this case it is safe to not update
+ * the max_array_access field because it is never used for fields
+ * of structures.
+ */
+ ir_variable *v = array->whole_variable_referenced();
+ if (v != NULL)
+ v->max_array_access = array->type->array_size() - 1;
+ }
+
+ /* From page 23 (29 of the PDF) of the GLSL 1.30 spec:
+ *
+ * "Samplers aggregated into arrays within a shader (using square
+ * brackets [ ]) can only be indexed with integral constant
+ * expressions [...]."
+ *
+ * This restriction was added in GLSL 1.30. Shaders using earlier
+ * version of the language should not be rejected by the compiler
+ * front-end for using this construct. This allows useful things such
+ * as using a loop counter as the index to an array of samplers. If the
+ * loop in unrolled, the code should compile correctly. Instead, emit a
+ * warning.
+ */
+ if (array->type->element_type()->is_sampler()) {
+ if (!state->is_version(130, 100)) {
+ if (state->es_shader) {
+ _mesa_glsl_warning(&loc, state,
+ "sampler arrays indexed with non-constant "
+ "expressions is optional in %s",
+ state->get_version_string());
+ } else {
+ _mesa_glsl_warning(&loc, state,
+ "sampler arrays indexed with non-constant "
+ "expressions will be forbidden in GLSL 1.30 "
+ "and later");
+ }
+ } else {
+ _mesa_glsl_error(&loc, state,
+ "sampler arrays indexed with non-constant "
+ "expressions is forbidden in GLSL 1.30 and "
+ "later");
+ }
+ }
+ }
+
+ /* After performing all of the error checking, generate the IR for the
+ * expression.
+ */
+ if (array->type->is_array()
+ || array->type->is_matrix()) {
+ return new(mem_ctx) ir_dereference_array(array, idx);
+ } else if (array->type->is_vector()) {
+ return new(mem_ctx) ir_expression(ir_binop_vector_extract, array, idx);
+ } else if (array->type->is_error()) {
+ return array;
+ } else {
+ ir_rvalue *result = new(mem_ctx) ir_dereference_array(array, idx);
+ result->type = glsl_type::error_type;
+
+ return result;
+ }
+}